Two-component permanent oxidative hair colorants comprising a tint component and an oxidizing component are commonly used in professional hair salons. The tint component contains so-called oxidative primary dyes which are small molecules (primary intermediates or couplers) and an alkalizing agent, usually ammonia. These primary dyes react with each other in the presence of an oxidizing agent to form larger, colored molecules. The tint component is thus mixed with the oxidizing component immediately prior to application to the hair to be colored and the resulting mixture is applied on hair for 10 to 50 mn usually for 15 to 35 mn. The oxidizing component may be for example a diluted stabilized solution of hydrogen peroxide. The mixture usually has an alkaline pH of between about 9.5 and 10.5.
Because the primary dyes are small enough to migrate into the hair shaft but the resulting colored molecules are too large to easily leave the hair, the resulting coloration is stable and undergo little fading. Furthermore, hydrogen peroxide, especially in the presence of ammonia, is capable of bleaching melanin, so that it is possible to obtain shades which are lighter or darker than the natural colour. Thus oxidative dye compositions comprising ammonia as alkalizing agent are often referred to as permanent hair colorants or “Level 3” hair colorant. Permanent hair colorants are for example marketed under the Koleston Perfect brand name by Wella Professional in Europe.
Demi-permanent hair colorants, also referred to as “level 2” colorants, are also two-component systems. They use primary dyes as in permanent hair colorants but differ in that they use other alkalizing agents than ammonia, in particular alkanolamines such as monoethanolamine (MEA) or aminomethylpropanol (AMP), and usually lower concentration of hydrogen peroxide (1 to 3 weight % (w. %) in the mixed product (“on-head” composition) compared to 3 to 6 w. % for permanent dyes). Other peroxides may also be used for Level 3 bleaching composition, e.g. persulfate, as oxidizing agent. Demi-permanent hair colorants usually provoke less melanin bleaching and thus less lift (i.e. removal) of natural hair color. The resulting dyes also penetrate less deeply in the hair shaft so that demi-permanent hair colorants can be less stable than permanent hair colorants. On the other hand, demi-permanent hair colorants are usually also less damaging to the hair structure than permanent hair colorants and the resulting hair color may also be more natural looking. Demi-permanent hair colorant compositions do not have the strong ammonia smell of permanent hair colorant and thus have a better consumer acceptance. A professional brand of demi-permanent dyes in Europe is for example Color Touch from Wella Professional.
Some oxidative colorant products sometimes referred to as lightening or bleaching products comprise little amount of precursor dyes (one can set an arbitrary limit at less than 0.3% by weight of precursor dyes of the composition on-head). For such products, the color change therefore mainly results in the degradation of the natural melanin of hair by the oxidizing agent in an alkaline environment.
Ammonia-free hair coloring products have been proposed with the goal to provide coloring results close to those obtained with permanent dyes containing ammonia. For example Schwarzkopf has launched in 2009 in Germany a two-component ammonia-free colorant product under the brand name Essensity. The alkalizing agent used is MEA and relatively high level of hydrogen peroxide is used (up to 7.7% on head).
U.S. Pat. No. 6,423,101, assigned to EUGENE PERMA discloses an ammonia-free composition for dyeing keratinous fibers, comprising an oxidant compound, coloring agent precursors and a non-volatile odorless alkalizing agent characterized in that it further comprises: a quaternized copolymer of dimethyldiallyl ammonium and acrylic acid; a quaternized silicone; an acrylic-itaconic copolymer esterified with one or several fatty alcohol's, optionally polyoxyethylenated. The composition is prepared using a two-component system with MEA as alkalizing agent. According to this Patent, the specific ternary complex claimed provides coloration which gives good coverage and resistance similar to coloration using ammonia.
US2010/0154141A1 assigned to L'Oreal discloses a process for coloring keratin materials comprising: applying to said keratin materials a coloring composition comprising a direct emulsion (A) comprising at least one fatty substance other than fatty acids present in an amount greater than 25% by weight; at least one surfactant; at least one alkaline agent; at least one colored or coloring entity chosen from direct dyes and oxidation dyes; and water in an amount greater than 5% by weight relative to the total weight of the direct emulsion (A); and a composition (B) comprising at least one oxidizing agent. The alkanolamine is preferably chosen from 2-amino-2-methyl-1-propanol and monoethanolamine.
Although hair coloring products obtained by mixing two components are most commonly used, products obtained by mixing three components have also been disclosed. US2008/0052841A1 assigned to LES PRODUITS VERNICO LTEE for example discloses a method for permanently modifying a color of keratinous fibers with a mixture of three compositions A, B and C, wherein said composition A comprises at least a reducing agent and optionally a coloring compound, said composition B comprises at least an alkalizing compound and said composition C comprises at least an oxidizing compound.
US2010/0223739A2 assigned to L'Oreal discloses a process and kit for dyeing keratin fibers, in which the following are applied to the fibers: an aqueous cosmetic composition (A) comprising at least one fatty substance and at least one surfactant; a cosmetic composition (B) comprising at least one alkaline agent, a cosmetic composition (C) comprising at least one oxidizing agent, wherein the amount of the at least one fatty substance in composition (A) is greater than 20% by weight relative to the total weight of composition (A), and when the process used is a process for dyeing keratin fibers, then cosmetic composition (B) further comprises at least one oxidation dye, at least one direct dye, or both.
Further patent applications assigned to L'Oreal disclose coloring compositions obtained by mixing three components. For example US2009/0191142 discloses a process for dyeing human keratin fibers in the presence of at least one oxidizing agent, comprising applying to the fibers at least one anhydrous composition (A) comprising at least one fatty substance and at least one surfactant, at least one composition (B) comprising at least one oxidizing agent, and at least one composition (C) comprising at least one dye chosen from direct and oxidation dyes, and at least one organic amine having a pKb at 25° C. of less than 12. The disclosure also relates to a multi-compartment device containing, in separate compartments, the compositions (A), (B), and (C); and a method of making a ready-to-use composition. The present disclosure also relates to an anhydrous composition comprising at least one fatty substance, at least one surfactant, at least one dye, and at least one organic amine. L'Oreal's US2009/0162309, US2009/0158533, US2010/0175705, US2010/0175706, US2010/0178264, US2010/0154137 also disclose three-component coloring compositions.
In addition, L'Oreal has launched in 2009 in Western Europe a three-component system for professional usage under the brand name INOA. The INOA products comprise a fatty component, a concentrated dye component and an oxidizing component to be mixed immediately before use. The fatty component comprises primarily mineral oil and does not comprise an alkalizing agent. The dye component comprises MEA as alkalizing agent. The 3 components are recommended to be mixed in a 40:16:60 weight ratio.
Although the prior art discloses using two or three components to obtain a permanent hair color result without ammonia, the prior art has not provided a versatile system for providing different level of lift and/or intensity of color at the discretion of the user based a single tint component.
Furthermore Level 2 and Level 3 products, even provided by the same company, usually are based on very different chassis. For example, although the INOA products from L'Oreal achieve or are close to achieve level 3 results without ammonia, they require the use of high level of a fatty phase and have a completely different formulation than other L'Oreal's Level 2 products. This increases complexity and costs.
The present inventors have now surprisingly found that it was possible to increase the lift provided by non-ammonia based oxidative two-component colorant products by mixing them with a third component. The third component comprises a non-alkalizing agent. It was surprisingly found that for example a conventional Level 2 product may achieve a lift up to a classic Level 3 product with the adjunction of the third alkalizing component.
It was also surprisingly found that the color shift in the three-component system of the invention relative to the two-component system was not significant. Thus the user can add the third component of the invention to a two-component based composition, in order to provide a composition having higher lift while achieving the same tonality. A further advantage is thus that existing two-component “Level 2” coloring products can be “boosted” into “Level 3” coloring products by the addition of this third component, thus extending the range of results achievable at very little cost and complexity.
Thus, the present invention provides a simple and cost-efficient system for providing at the choice of the user a first or a second coloring compositions having relatively less or relatively more lift based on the same tint component.